And though the actor sticks to his on-screen love interest's (River Song, played by
Alex Kingston) motto of "no spoilers," we did get a little bit out of him over what to expect from the Aug. 27 return episode, "Let's Kill Hitler."

"Alex Kingston is bloody brilliant in it," he gushed. "We learn a lot more about the Doctor and River as this latter part of the series goes on... and certainly by episode 13 there's a lot of 'whoa' moments."

So what will that mean for the Doctor's relationship with River's recently-revealed parents, Amy (
Karen Gillan) and Rory (
Arthur Darvill). Well, you'll have to wait and see. But we will be seeing darker bits to Smith's Doctor.

"What's really interesting, i think, about the Doctor," he says, "particularly in these last moments of the series, we've explored seeing him really angry and exploring the darker tones of him. What's great about the Doctor is you can mix dark and light within the space of a sentence. He can go from A to Z like that."

[Insert charming, emphatic Matt Smith finger snap here.]

The character's growth and the show's constantly-increasing global presence is also one of the things that made him jump at the chance to sign up for Season 7.

"We're growing," he says. "I think the guys at BBC America have supported and invested in the show, [for] which I'm very grateful... We've got a long way to go, and hopefully we'll continue to grow."

Watch the full video interview above, which includes Smith's thoughts on the 50th anniversary and the hilarity that is Comic-Con.